A prospective study of the impact of smoking on outcomes in bipolar and schizoaffective disorder

BackgroundTobacco smoking is more prevalent among people with mental illnesses, including bipolar disorder, than in the general community. Most data are cross-sectional, and there are no prospective trials examining the relationship of smoking to outcome in bipolar disorder. The impact of tobacco smoking on mental health outcomes was investigated in a 24-month, naturalistic, longitudinal study of 240 people with bipolar disorder or schizoaffective disorder.MethodParticipants were interviewed and data recorded by trained study clinicians at 9 interviews during the study period.ResultsComparisons were made between participants who smoked daily (n = 122) and the remaining study participants (n = 117). During the 24-month study period, the daily smokers had poorer scores on the Clinical Global Impressions–Depression (P = .034) and Clinical Global Impressions–Overall Bipolar (P = .026) scales and had lengthier stays in hospital (P = .012), compared with nonsmokers.LimitationsSmoking status was determined by self-report. Nicotine dependence was not measured.ConclusionThese findings suggest that smoking is associated with poorer mental health outcomes in bipolar and schizoaffective disorder.